Final Examination (Proteins and Nucleic acids)

1. An amino acid is a compound that contains at least one amino group and one amide group. two amino groups and one carboxylic acid group. one hydroxyl group and one methyl group. one carboxylic acid group and one amino group. one methyl group and one amide group. 2. A peptide bond (also called an amide bond) joins two amino acids together. What atoms are linked by this bond? C — O C — H C — N N — S S — C 3. Which one of these elements is not found in proteins? S P C O N 4. An essential amino acid is one that must be included in the diet. contains no sulfur. occurs in all types of proteins. is necessary for vitamin production. the body can synthesize. 5. Which one of these choices is the general structural formula of an amino acid? 6. The functional groupfound in proteins is called a (an) amide. carboxylic acid. amine. amino acid. dipeptide. 7.Which of the structures below corresponds to the dipeptide alanylserine? Note the following structures: 8. Which of the structures below corresponds to the dipeptide serylalanine? Note the following structures: 9.Which of these choices is not an intermolecular force that affects the structure of a protein? hydrogen bond dispersion force adhesive force ionic force dipole-dipole force 10. The secondary structure of a protein is the configuration of those parts of the chain stabilized by a regular pattern of covalent bonds between C and O groups of the backbone of the chain. configuration of those parts of the chain stabilized by a regular pattern of hydrogen bonds between CO and NH groups of the backbone of the chain. specific order of amino acids in the chain. overall three-dimensional structure of the molecule. overall arrangement of several polypeptide chains into one functional unit. 11. A protein that has been reversibly denatured has temporarily lost part or all of its secondary or tertiary structure. temporarily lost part or all of its primary structure. been genetically modified due to errors in the nucleotides in the parent DNA. temporarily lost its amino acid residues. temporarily lost the hydrogen bonding between nitrogenous bases. 12. Which of these molecules is a product of the hydrolysis of DNA? acetic acid glucose adenine ribose water 13. Phosphorus is an essential mineral element. It is an important atom in which one of the following? amino acids proteins polyethylene nylon DNA 14. The backbone of a strand of nucleic acid consists of phosphate units only. phosphate and sugar units. polyester. phosphate, sugar, and nitrogen base units. sugar units only. 15. Which choice contains all three molecular units found in nucleotides? phosphate, sugar, amino acid amino acid, nitrogen-containing base, sugar carboxylic acid, sugar, protein phosphate, nitrogen-containing base, sugar sugar, amino acid, protein 16. Which choice lists both the sugar and the nitrogen base that are a part of RNA but are not a part of DNA? deoxyribose and thymine ribose and deoxyribose ribose and uracil uracil and thymine ribose and thymine 17.Which one of these molecules is part of the make-up of both DNA and RNA? deoxyribose ribose phosphate thymine uracil 18. Which nitrogen base is found in RNA but not in DNA? adenine cytosine guanine thymine uracil 19. Cysteine and methionine are unique among the twenty amino acids essential to living organisms in that they are chiral. contain an aromatic ring. do not form dipolar ions. contain sulfur. cannot join with other amino acids to form peptides. 20. The b-pleated sheet configuration of proteins is relatively inelastic. never occurs in nature. is structurally weak. contains no peptide bonds. does not involve hydrogen bonds to other proteins.